People who have taken certain antibiotics repeatedly may be at an increased risk of type 2 diabetes, according to a new study. Researchers found that people in the study who had ever been prescribed two or more courses of specific types of antibiotics were more likely to be diagnosed with type 2 diabetes than people who had never been prescribed these antibiotics, or had taken just one course. The antibiotics in the study came from one of four categories: penicillins, cephalosporins, quinolones and macrolides.